Needle assembly including obturator with safety reset

ABSTRACT

A needle assembly is able to collect a sample of biological material in a needle of the assembly. The needle assembly has a safety shield capable of being moved on the needle assembly to cover a sharp tip of the needle assembly. The shield can be locked in place over the sharp tip by a locking mechanism. The assembly further includes an obturator that can be inserted into the needle to remove the sample from the needle. A reset member, which in some embodiments is associated with the obturator, is capable of operatively engaging the locking mechanism to release the locking mechanism and allow the shield to be moved away from the sharp tip.

BACKGROUND OF THE INVENTION

This invention relates generally to needle assemblies and moreparticularly to needle assemblies that have shields to cover sharp endsof needles.

Needle assemblies of the present invention have particular, although notexclusive application in the field of medicine and have needles withsharpened ends for use in piercing the skin to withdraw materials asneeded. The needle is supported by some other structure that is used tomanipulate the needle. The most common example is a syringe. However,some needle assemblies require the application of substantial force inuse. One example of such a needle assembly is a bone marrow needleassembly that is used to penetrate cortical bone to reach theintramedullary canal for withdrawing liquid or a biopsy sample of boremarrow, or for infusing the canal with a selected material. Typically,the needle includes a cannula and a stylet that is received in thecannula and has a hard, sharp tip that can penetrate cortical bone. Thetip projects out from the distal end of the cannula. The stylet can bewithdrawn from the cannula after the needle penetrates the bone to theso that the hollow interior of the cannula can be used as a conduit forliquid or a receptacle to collect bone marrow.

In order to penetrate cortical bone, a substantial amount of force mustbe applied to the needle. For this reason, bone needle assembliesconventionally mount the needle in a handle that is sized and shaped sothat the technician may comfortably grip the handle and apply the forcenecessary to penetrate the bone. The handle may comprise two handlemembers that can be selectively put together and separated for insertingthe stylet into the cannula and removing the stylet from the cannula. Aproximal handle member mounts the stylet and a distal handle membermounts the cannula. “Proximal” and “distal” refer to the relativelocation of the handle members to the technician when the needleassembly is in use. The proximal handle member is in contact with thepalm of the technician's hand in use, and the distal handle member is onthe opposite side of the proximal handle member from the palm.

Some needle assemblies, including bone needle assemblies, haveassociated safety mechanisms that shield the sharp tips of the needlecomponents when they are not needed and after they have becomecontaminated with potentially hazardous biological material. The safetymechanism includes a shield and usually a mechanism for locking theshield in place over the sharpened tip. As a matter of convenience, andto enhance the probability that the safety feature will be used by amedical technician, the safety feature may be secured to the needleassembly. However, the safety feature must be retained out of the waywhen the needle assembly is being used, for example, to collect a liquidor solid sample from the intramedullary canal. The safety feature thenmust be released from its stowed position and moved to an operativeposition in which its shield covers the sharpened tip of the needle.

In cases where a sample (e.g., a bone marrow sample) is collected by theneedle assembly, the sample has to be removed from the needle assembly.An obturator is a device including a long thin shaft, and in some casesincludes a blunt tip, that can fit inside the cannula for pushing thesample of bone marrow out of the cannula. This can be done with thesafety shield in position covering the sharp end of the cannula toprotect the technician. In some cases it will be determined that thesample is not satisfactory and it will be necessary to obtain a secondsample. It is not necessary to use a new needle assembly, because theneedle assembly would be reused on the same patient. However, the shieldis held in place over the tip of the needle assembly making it unusablefor a collecting a second sample. Accordingly, there is a need for aneedle assembly that can be easily reset for multiple uses, but whichwill not result in inadvertent release of the safety shield.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a needle assembly generallycomprises mounting structure and a needle mounted on the mountingstructure and extending outwardly therefrom. The needle has alongitudinal axis, a sharp end and a central axial passageway. A safetyshield associated with the needle comprises a tubular housing adaptedfor movement relative to the needle between a stowed position in whichthe tubular housing is spaced from the sharp end of the needle and adeployed position in which the tubular housing covers the sharp end. Alocking mechanism of the safety shield is adapted to releasably lock thetubular housing in position covering the sharp end of the needle. Anobturator includes a shaft sized and shaped for reception in the centralaxial passageway of the needle. A reset member operatively connected tothe shaft is selectively operatively engageable with the lockingmechanism of the safety shield for releasing the locking mechanism topermit the tubular housing to be move away from the sharp end of theneedle.

In another aspect of the present invention, an obturator may be usedwith a needle assembly to remove a sample of biological materialcollected in the needle assembly. The needle assembly includes a safetyshield having a locking mechanism capable of locking the safety shieldin place on the needle assembly. The obturator generally comprises agrip for holding and manipulating the obturator and a shaft extendingfrom the grip. The shaft is sized and shaped for reception in a centralaxial passageway of the needle assembly for pushing the sample out ofthe central axial passageway. A reset member operatively connected tothe grip and adapted for engagement with the locking mechanism of thesafety shield for releasing the locking mechanism.

In yet another aspect of the present invention, a method for obtaining asample of biological material from a subject using a needle assembly andresetting the needle assembly for subsequent use, generally comprisesthe step of pushing a needle of the needle assembly having a centralaxial passageway into the subject to collect a sample of biologicalmaterial from the subject in the central axial passageway. A shaft of anobturator is inserted into the central axial passageway of the needle topush the sample out of the central axial passageway. The obturator ismanipulated to bring a reset member on the obturator into engagementwith a locking mechanism of a shield on the needle assembly to releasethe locking mechanism. The shield is then moved.

In a further aspect of the present invention, a needle assemblygenerally comprises mounting structure and a needle mounted on themounting structure and extending outwardly therefrom. The needle has alongitudinal axis, a sharp end and a central axial passageway. A safetyshield associated with the needle comprises a tubular housing adaptedfor movement relative to the needle between a stowed position in whichthe tubular housing is spaced from the sharp end of the needle and adeployed position in which the tubular housing covers the sharp end. Alocking mechanism is adapted to releasably lock the tubular housing inposition covering the sharp end of the needle. The tubular housing hasdistal and proximal ends and at least one peripheral slot extendingradially inwardly from the periphery and axially along the housing fromthe distal end of the housing. A reset key adapted to actuate release ofthe locking mechanism to permit the shield to be moved relative to theneedle comprises a support and at least one rib on the support sized andarranged for reception in the peripheral slot of the tubular housing forentering the tubular housing to actuate release of the lockingmechanism.

In yet a further aspect of the present invention, a reset key for use inreleasing a locking mechanism of a safety shield covering a sharp tip ofa needle for movement of the safety shield relative to the needlegenerally comprises a support defining a central open space sized andshaped for receiving at least a portion of the safety shield. Ribsmounted on the support and located at positions spaced circumferentiallyof each other generally around the perimeter of the central open spaceare shaped and arranged for reception in slots on the safety shield whenthe safety shield is received in the central open space for actuatingrelease of the locking mechanism.

In still a further aspect of the present invention, a reset key for usein releasing a locking mechanism of a safety shield covering a sharp tipof a needle for movement of the safety shield relative to the needlegenerally comprises a shroud sized and shaped for receiving at least amajority of the safety shield therein. A reset member associated withthe shroud can actuate release of the locking mechanism when the safetyshield is received in the shroud.

In another aspect of the present invention, a needle assembly generallycomprises mounting structure and a needle mounted on the mountingstructure and extending outwardly therefrom. The needle has alongitudinal axis, a sharp end, and a central axial passageway. A safetyshield associated with the needle comprises a tubular housing adaptedfor movement relative to the needle between a stowed position in whichthe tubular housing is spaced from the sharp end of the needle and adeployed position in which the tubular housing covers the sharp end. Alocking mechanism is adapted to releasably lock the tubular housing inposition covering the sharp end of the needle. An unlocking mechanism isadapted to engage the locking mechanism to unlock the tubular housingfrom the needle. An obturator includes a shaft sized and shaped forreception in the central axial passageway of the needle. A reset memberoperatively connects to the shaft and selectively engages the unlockingmechanism of the safety shield for moving the unlocking mechanism intoselective engagement with the locking mechanism for releasing thelocking mechanism to permit the tubular housing to move away from thesharp end of the needle.

In yet another aspect of the present invention, a resettable needlesafety shield for use in selectively shielding and unshielding a sharptip of a needle generally comprises a housing sized and shaped forsubstantially surrounding the sharp needle tip to hinder access to thesharp tip and a locking mechanism associated with the housing. Thelocking mechanism is adapted to lock the housing in positionsubstantially surrounding the sharp needle tip. An unlocking mechanismis associated with the housing for movement relative to the housingbetween a first position in which the locking mechanism is free to lockthe housing in position relative to the sharp needle tip and a secondposition in which the unlocking mechanism releases the locking mechanismto permit movement of the housing relative to the needle.

In still another aspect of the present invention, a resettable needlesafety shield for use in selectively shielding and unshielding a sharptip of a needle generally comprises a housing sized and shaped forsubstantially surrounding the sharp needle tip to hinder access to thesharp tip and a locking mechanism associated with the housing. Thelocking mechanism is adapted to lock the housing in positionsubstantially surrounding the sharp needle tip. The housing includes anend wall having at least one hole therein arranged in relation to thelocking mechanism for receiving structure through the end wall for usein releasing the locking mechanism.

In a further aspect of the present invention, an obturator for use witha needle assembly to remove a sample of biological material collected ina hollow needle of the needle assembly generally comprises a grip forholding and manipulating the obturator. A shaft extending from the gripis sized and shaped for reception in a central axial passageway of theneedle assembly for pushing the sample out of the central axialpassageway. A shield is slidably supported on the shaft for engaging andshielding a sharp end of the hollow needle when the obturator shaft isbeing inserted into the needle to remove the sample.

In yet a further aspect of the present invention, a needle assemblygenerally comprises a mounting structure and a needle mounted on themounting structure and extending outwardly therefrom. The needle has alongitudinal axis, a sharp end and a central axial passageway. A safetyshield is associated with the needle and comprises a tubular housinghaving an open end. The tubular housing is adapted for movement relativeto the needle between a stowed position in which the tubular housing isspaced from the sharp end of the needle and a deployed position in whichthe tubular housing covers the sharp end. A locking mechanism is adaptedto releasably lock the tubular housing in position covering the sharpend of the needle. A reset member is selectively operatively engageablewith the locking mechanism of the safety shield for releasing thelocking mechanism to permit the tubular housing to be move away from thesharp end of the needle. The safety shield further comprises a resilientmembrane substantially covering the open end of the tubular housing. Themembrane is resiliently deformable upon engagement with the reset memberto permit the reset member to move into operative engagement with thelocking mechanism for releasing the locking mechanism.

In another aspect of the present invention, a needle assembly generallycomprises mounting structure and a needle mounted on the mountingstructure and extending outwardly therefrom. The needle has alongitudinal axis, a sharp end and a central axial passageway. A safetyshield associated with the needle comprises a tubular housing having anopen end. The tubular housing is adapted for movement relative to theneedle between a stowed position in which the tubular housing is spacedfrom the sharp end of the needle and a deployed position in which thetubular housing covers the sharp end. A locking mechanism is adapted toreleasably lock the tubular housing in position covering the sharp endof the needle. A reset member supported on the safety shield for slidingmovement relative to the safety shield generally parallel to a outersurface of the safety shield, the resent member being selectivelyoperatively engageable with the locking mechanism of the safety shieldfor releasing the locking mechanism to permit the tubular housing to bemove away from the sharp end of the needle.

Other objects and features of the present invention will be in partapparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of a bone needle assembly including anobturator;

FIG. 2 is a fragmentary partial section of the needle assembly with theobturator engaging a safety shield of the needle assembly and partsbroken away to show internal construction;

FIG. 3 is the fragmentary elevation of FIG. 2 but showing the obturatorinserted to a position in which a sample collected by the needleassembly is pushed out of the needle assembly;

FIG. 4 is the fragmentary elevation of FIG. 2 but showing use of theobturator to reset a locking mechanism of the safety shield;

FIG. 5 is the fragmentary elevation of FIG. 2 but showing the safetyshield being withdrawn from a sharp end of the needle assembly afterrelease of the locking mechanism;

FIG. 6 is an end elevation of the obturator;

FIG. 7 is a perspective of a needle assembly of a second embodimentincluding an obturator;

FIG. 8 is a fragmentary partial section of the needle assembly of FIG. 7illustrating the obturator just prior to insertion into the needleassembly and parts broken away to show internal construction;

FIG. 9 is the fragmentary partial section of FIG. 8 but showing theobturator inserted into the needle assembly a distance sufficient toremove a sample from the obturator;

FIG. 10 is the fragmentary partial section of FIG. 8 but showing a resetfeature of the obturator entering a safety shield of the needleassembly;

FIG. 11 is the fragmentary partial section of FIG. 8 but showing theobturator resetting a locking mechanism of the safety shield to permitthe safety shield to be withdrawn from a sharp end of the needleassembly;

FIG. 12 is a perspective of a needle assembly of a third embodimentincluding an obturator;

FIG. 13 is a perspective of a modified obturator similar to that of FIG.12;

FIG. 14 is a fragmentary partial section showing the obturator of FIG.13 inserted into the needle assembly but prior to resetting a lockingmechanism thereof with parts broken away to show internal construction;

FIG. 15 is a perspective of an obturator of a needle assembly of afourth embodiment;

FIG. 16 is a fragmentary partial section of the obturator partiallyinserted into the needle assembly with parts broken away to showinternal construction;

FIG. 17 is a perspective of a bone needle assembly of a fourthembodiment including an obturator;

FIG. 18 is a fragmentary partial section of the needle assembly with theobturator entering a safety shield of the needle assembly;

FIG. 19 is the fragmentary elevation of FIG. 18 but showing theobturator inserted to a position in which a sample collected by theneedle assembly is pushed out of the needle assembly;

FIG. 20 is the fragmentary elevation of FIG. 18 but showing use of theobturator to reset a locking mechanism of the safety shield;

FIG. 21 is the fragmentary elevation of FIG. 18 but showing the safetyshield set for withdrawal from a sharp end of the needle assembly afterrelease of the locking mechanism;

FIG. 22 is a fragmentary perspective of the obturator with parts brokenaway to show internal construction;

FIG. 23 is an end view of the obturator;

FIG. 24 is a fragmentary perspective of the obturator entering thesafety shield;

FIG. 25 is a fragmentary partial section of a needle assembly of a fifthembodiment in a configuration similar to FIG. 19;

FIG. 26 is a fragmentary perspective of an obturator of the needleassembly of FIG. 25;

FIG. 27 is a fragmentary perspective of an end of a shield of the needleassembly of FIG. 25;

FIG. 28 is a perspective of a bone needle assembly of a sixth embodimentincluding an obturator;

FIG. 29 is a fragmentary partial section of the needle assembly with theobturator entering a safety shield of the needle assembly;

FIG. 30 is the fragmentary elevation of FIG. 29 but showing theobturator inserted to a position in which a sample collected by theneedle assembly is pushed out of the needle assembly;

FIG. 31 is the fragmentary elevation of FIG. 29 but showing use of theobturator to reset a locking mechanism of the safety shield;

FIG. 32 is the fragmentary elevation of FIG. 29 but showing the safetyshield being withdrawn from a sharp end of the needle assembly afterrelease of the locking mechanism;

FIG. 33 is a fragmentary perspective of the obturator with parts brokenaway to show internal construction;

FIG. 34 is an end view of the obturator;

FIG. 35 is a fragmentary perspective of the needle assembly showing thesafety shield;

FIG. 36 is a perspective view of an obturator of a needle assembly of aseventh embodiment incorporating an integral funnel guide and resetfeature;

FIG. 37 is a perspective view of the obturator of FIG. 36 and anotherpart of the needle assembly during resettable engagement;

FIG. 38 is the perspective of FIG. 37 with parts broken away to showinternal construction;

FIG. 39 is an enlarged fragment of the perspective of FIG. 37;

FIG. 40 is the perspective of FIG. 37 with the obturator insertedthrough a needle of the needle assembly;

FIG. 41 is the perspective of FIG. 40 with parts broken away to showinternal construction;

FIG. 42 is an enlarged fragment of the perspective of FIG. 41;

FIG. 43 is a perspective view of an obturator;

FIG. 44 is a perspective view of a funnel for guiding an obturator;

FIG. 45 is a cutaway view of a funnel placed over a needle;

FIG. 46 shows locating features on the safety shield for guiding theobturator to the inner diameter of the needle;

FIG. 47 shows an obturator inserted into a funnel;

FIG. 48 is a perspective view of an alternative embodiment of themedical needle shield apparatus according to the present disclosure;

FIG. 49 is a cutaway view of the embodiment shown in FIG. 48;

FIG. 50 is an enlarged view of the safety shield of the embodiment shownin FIG. 48;

FIG. 51 is a cutaway view of the safety shield having a needle inserted;

FIG. 52 is a perspective view of the safety shield having an obturatorinserted;

FIG. 53 is an enlarged perspective view of the safety shield having anadjustable guide;

FIG. 54 is an enlarged perspective view of the safety shield having anadjustable guide with a reset area;

FIG. 55 is a guiding member integrated with an obturator;

FIG. 56 is a guiding member integrated with an obturator having aspring;

FIG. 57 is an enlarged view of the guiding member shown in FIG. 56;

FIG. 58 is an elevation of a guiding member integrated with an obturatorof another embodiment just prior to mating with a cannula;

FIG. 59 is the elevation of FIG. 58 with the obturator inserted into thecannula;

FIG. 60 is an obturator handle having a resettable feature;

FIG. 61 is an obturator handle having a resettable feature;

FIG. 62 is an obturator handle having a resettable feature inserted intoa needle;

FIG. 63 is an alternative embodiment of the medical needle shieldapparatus according to the present disclosure;

FIG. 64 is a safety shield incorporating a reset member; and

FIG. 65 is a longitudinal section of the safety shield.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION

Referring now to the drawings and in particular to FIG. 1, a medicalinstrument constructed according to the principles of the presentinvention is shown in the form of a bone needle assembly, generallyindicated at 10. The bone needle assembly includes a handle 12 (broadly,“mounting structure”), a needle 14 and a cannula safety shield 16, allreference numbers indicating their subjects generally. The needle 14includes a stylet 18 and a cannula 20 that can receive the stylet. Thehandle 12 includes a first or proximal handle member (indicatedgenerally at 22) mounting the stylet 18, and a second or distal handlemember (indicated generally at 24) mounting the cannula 20. It will beunderstood that a needle could include only a single component part, ormore than two parts within the scope of the present invention.Similarly, a handle could be a single part or more than two parts. Themounting structure for the needle 14 can be other than a handle withoutdeparting from the present invention. The needle assembly 10 furtherincludes an obturator 26 (described more fully below) that may be usedto remove a sample captured in the cannula 20.

The cannula 20 has a central axial passage extending the length of thecannula and opening at both ends of the cannula. A distal tip 28 of thecannula 20 is beveled and sharpened. A proximal end portion of thecannula 20 is received in the distal handle member 24. The stylet 18 issolid and includes a sharp distal tip, and a proximal end portionreceived in the proximal handle member 22. The stylet 18 can be insertedthrough the axial passage opening in the proximal end portion of thecannula 20 and received entirely through the axial passage of thecannula so that its sharp distal tip projects axially outward from thedistal tip 28 of the cannula. The stylet 18 provides the tool forpenetrating the cortical bone, and can be removed from the cannula 20once the intramedullary canal is accessed by the needle 14.

The handle 12 formed by the proximal and distal handle members 22, 24has an ergonomic shape that can be comfortably received in a medicaltechnician's hand, and allows the technician to easily control theneedle assembly 10 as he or she applies the substantial forces needed topenetrate the bone. More specifically, the top or proximal surface 38 ofthe proximal handle member 22 is rounded in conformance with the shapeof the palm of the hand. The bottom or distal surface 40 of the distalhandle member 24 is also rounded, but is undulating in shape therebyforming finger wells 40A for receiving the technician's fingers. Theform of the handle can be other than described herein without departingfrom the scope of the present invention. The proximal and distal handlemembers 22, 24 can be connected together in a suitable manner when thestylet 18 is received in the cannula 20, so that the handle 12 actsessentially as a single piece when used to drive the needle 14 through apatient's skin and into the bone. The proximal and distal handle members22, 24 can be disconnected and moved apart for removing the stylet 18from the cannula 20.

The cannula safety shield 16 may be moved to cover the distal tip 28 ofthe cannula 20 after the needle assembly 10 has been used. The safetyshield 16 includes a generally tubular housing 50 and an internallocking mechanism (generally indicated at 52 in FIG. 2) capable ofreleasably locking the tubular housing in position covering the distaltip 28 of the cannula 20. The tubular housing 50 may have any shape thatis suitable for hindering access to the sharp tip 28. The tubularhousing 50 need not be solid or circular in cross section within thescope of the present invention. The tubular housing 50 and handle 12 mayinclude structure to secure the tubular housing in a retracted positionadjacent the handle when not needed. An example of such structure isshown in co-assigned U.S. application SER. NO. 11/146,173, filed Jun 6,2005, the disclosure of which is incorporated herein by reference.

The locking mechanism 52 inside the safety shield 16 comprises a cantingmember including a base 56 having a hole and a pair of arms 60 (only oneis shown) extending generally axially from the base. The arms 60 areconnected together by a U-shaped member 62 at their ends and each has anupwardly (as oriented in the figures) bent tab 64 (only one is shown)projecting axially outward from the end. Before the locking mechanism 52is activated to lock the tubular housing 50 in position, the ends of thearms 60 ride on the exterior surface of the cannula 20. This holds thecanting member so that the base 56 is orthogonal so the longitudinalaxis of the cannula 20 and the base can move along the cannula (with thesafety shield 16), with the cannula sliding unimpeded through the holein the base. Once the ends of the arms 60 pass the distal tip 28 of thecannula 20, the locking mechanism 52 is weighted so that the ends of thearms move in a generally radial direction toward an opposite side of thelongitudinal axis of the needle 14. This causes the base 56 of thecanting member to cant relative to the axis of the needle 14 so that thehole in the base is no longer orthogonal to the axis of the cannula. Asa result, the base 56 at the edge of the hole grippingly engages thecannula 20 to lock the safety shield 16 in place. It will be understoodthat a locking mechanism could take on other forms than shown anddescribed without departing from the scope of the present invention.Moreover, the canting member may take on other configurations within thescope of the present invention.

The needle assembly 10 is driven into the bone by grasping the handle 12and pushing the stylet 18 through the skin, underlying tissue andcortical bone. Once this penetration has been achieved, the stylet 18 isno longer required. The proximal handle member 22 is disconnected fromthe distal handle member 24 and moved axially away from the distalhandle member so that the stylet 18 slides out of the central axialpassageway of the cannula 20 while the cannula remains in the bone. Inorder to collect a sample of bone marrow, the distal handle member isadvanced further into the bone. The sharp tip 28 of the cannula 20 cutsinto the bone marrow and a sample is received in the central axialpassageway of the cannula. The cannula 20 can then be withdrawn from thepatient by pulling on the distal handle member 24. The sample remainslodged in the central axial passageway of the cannula 20 near the sharptip 28. It will be understood that a needle assembly may be used tocollect a sample other than of bone marrow within the scope of thepresent invention.

The obturator 26 is used to remove a lodged sample of bone marrow thathas been collected in the central axial passageway of cannula 20. Theobturator 26 includes a grip 68 and a long, thin shaft 70 extending fromthe grip that is sized to be received in the central axial passageway ofthe cannula 20 in generally close fitting relation therein. The grip 68is sized and shaped to be grasped by a user for manipulating theobturator 26, as will be described. A tubular reset member 72 extendsfrom the grip 68 in the same direction as the shaft 70 and is generallycoaxial with the shaft in the illustrated embodiment. The reset member72 has an open end 73 opposite the grip 68. A coil compression spring 74surrounds the reset member 72 and is operatively secured to the grip 68.An annular aligning device in the form of a cap 76 is slidably mountedon the free end of the shaft 70 (opposite the grip 68), and is capableof centering the shaft relative to the tubular housing 50. In oneversion (not shown) the cap 76 may be attached to the spring 74 for usein retaining the cap on the obturator 26. The cap 76 has an opening 78having an annular, resilient membrane that can engage and center theshaft 70 in the opening. As shown in FIG. 2, the cap receives a distalend portion of the tubular housing 50 in generally close-fittingrelation so that the shaft 70 of the obturator 26 is aligned with thecentral axial passageway of the cannula 20. The cap 76 and tubularhousing 50 may be formed so that the cap has a releasable, snap-actingattachment with the housing when engaging the housing. However, theattachment may be omitted or take on other forms without departing fromthe scope of the present invention.

FIG. 2 illustrates the initial position of the obturator 26 with the cap76 engaging the proximal end of the tubular housing 50. The free end ofthe shaft 70 has not yet entered the central axial passageway of thecannula 20. The grip 68 is pushed to advance the shaft 70 into thecentral axial passageway, which pushes the sample toward the proximalend of the central axial passageway. As shown in FIG. 3, the shaft 70 isadvanced until it protrudes out of the proximal end of the central axialpassageway, thereby pushing the sample (not shown) out of the cannula 20where it can be collected in a Petri dish or other suitable container.As the shaft 70 is advanced, it slides through the cap 76. The lockingmechanism 52 remains engaged so that the safety shield 16 does not move.In the position shown in FIG. 3, the spring 74 surrounding the resetmember 72 engages the cap 76, but is not substantially deflected by thisengagement. Thus, the technician experiences slight resistance tofurther inward movement of the shaft 70 into the central axialpassageway of the cannula 20.

The technician may observe the sample ejected from the central axialpassageway of the cannula 20. If it is determined that the sample issatisfactory, the obturator 26 can be pulled so that the shaft 70 slidesback through and out of the cannula 20. The needle assembly 10 can bediscarded, or possibly but less likely, cleaned and sterilized for asubsequent use. However, if the sample is not satisfactory it will benecessary to obtain a second sample. This can be done using the sameneedle assembly 10, but the tubular housing 50 is locked in place by thelocking mechanism 52 over the sharp tip 28 of the cannula 20. Thetubular housing 50 needs to be moved away from the tip 28 before theneedle assembly 10 can be used to obtain a second sample.

The obturator 26 of the present invention is particularly adapted topermit the tubular housing 50 to be released and moved back from thesharp tip 28 of the cannula 20. From the position shown in FIG. 3, thegrip 68 can be advanced toward the tubular housing 50 against the biasof the spring 74 so that the reset member 72 is received into thetubular housing and engages the locking mechanism 52. More particularly,the tabs 64 of the canting member engage a leading free edge portion 80of the reset member 72 so that the reset member wedges the cantingmember up to a position in which the base is again substantiallyorthogonal to the axis of the cannula 20, as shown in phantom in FIG. 4.The open end 73 can receive a portion of the cannula 20 to allow thereset member 72 to be advanced far enough to reset the locking mechanism52. Movement of the canting member in this manner positions the hole inthe base 56 so that the cannula 20 can slide easily through the cantingmember. Thus as shown in FIG. 5, the tubular housing 50 can be graspedto pull back the safety shield 16 toward the distal housing member 24 sothat the sharp tip 28 of the cannula 20 is once again exposed. Theobturator shaft 70 can be removed and the stylet 18 can be reinsertedinto the cannula 20 for a second collection of a sample. It will beappreciated that the spring 74 inhibits the accidental release of thelocking mechanism 52. The technician must intentionally overcome theresisting bias of the spring to de-activate the locking mechanism 52.

Referring now to FIGS. 7-11, a needle assembly 110 of a secondembodiment is shown to comprise a handle 112 and a needle 114 extendingfrom the handle. A cannula safety shield 116 received on the cannula 120can be slid down to cover the sharp tip 128 of the cannula. Theconstruction and operation of the handle 112 and needle 114 aresubstantially the same as for the handle 112 and needle 114 of theneedle assembly 110 of the first embodiment. The same referencecharacters will be used to indicate corresponding parts of the needleassembly 110 of the second embodiment, plus “100”. Moreover, the handle112 and needle 114 will not be further described in view of theirsimilarity to the first embodiment. The safety shield 116 includes atubular housing 150 and a locking mechanism 152. The locking mechanism152 may be substantially the same as the locking mechanism 152 of thefirst embodiment. The tubular housing 150 is similar to the tubularhousing 150 of the first embodiment. However, a proximal end of thetubular housing 150 would be open except for an annular, flexiblemembrane 151 (broadly, “an aligning device”) that covers the open end.The membrane 151 has a central aperture 153 that is aligned with theproximal opening of the central axial passageway in the cannula 120. Themembrane 151 is used to guide an obturator 126 into the central axialpassageway, as will be described.

The obturator 126 comprises a grip 168 and a long, thin shaft 170extending from the grip and sized for being received in the centralaxial passageway of the cannula 120. The obturator 126 further includesa tubular reset member 172 projecting from the grip 168 and surroundingthe portion of the shaft 170 adjacent to the grip. The construction ofthe obturator 126 is similar to the obturator 126 of the firstembodiment, except that there is no spring 174 or annular cap 176.

FIGS. 8-11 illustrate the operation of the obturator 126 of the secondembodiment to remove a bone marrow sample (not shown) from the centralaxial passageway of the cannula 120 and, if desired, to de-activate thelocking mechanism 152 of the safety shield 116 to permit the shield tobe withdrawn from the sharp tip 128 of the cannula to reset the needleassembly 110 for a second use. As shown in FIG. 8, the medicaltechnician aligns the shaft 170 with the aperture 153 in the membrane151 of the safety shield 116, which results in the shaft also beingaligned with the central axial passageway of the cannula 120. The shaft170 is then inserted through the aperture 153 and into the central axialpassageway, as shown in FIG. 9. It will be appreciated that the membrane151 engages the shaft 170 when the shaft is inserted into the aperture153 and thereby operates to guide the shaft into the central axialpassageway. However, other structure for guiding the obturator shaft 170may be provided, or guiding structure may be entirely omitted withoutdeparting from the scope of the present invention. The shaft 170 issized in length so that at about the same time as a leading edge portion180 of the reset member 172 engages the membrane 151, or slightlybefore, the shaft will have passed completely through the cannula 120and project out the proximal end thereof. The sample (not shown) willhave been ejected from the cannula 120 at this point. The reset member172 may engage the membrane 151, which provides a slight resistance tofurther advancement of the shaft 170 into the safety shield 116 andcentral axial passageway of the cannula 120. This signals to theoperator that the obturator 126 has been pushed far enough into thecannula 120.

If the sample is satisfactory, the obturator 126 can be withdrawn fromthe cannula 120 and tubular housing 150, and the needle assembly 110discarded. However, if a second bone marrow sample needs to be taken,the obturator 126 can be advanced from the position shown in FIG. 9further into the safety shield 116. As shown in FIG. 10, the resetmember 172 deflects and stretches the membrane 151, causing the aperture153 to enlarge to the extent that the reset member 172 is admitted intothe tubular housing 150 through the aperture. The reset member 172 isthe only part of the obturator shown in section in FIG. 10. The resetmember 172 continues to advance to the position in FIG. 11. As the resetmember 172 advances, the leading edge portion 180 engages the tabs 164of the locking mechanism 152 pushing the locking mechanism back to itsposition where the safety shield 116 is free to slide along the cannula120. Thus in substantially the same was as shown in FIG. 5, the tubularhousing 150 can be grasped and moved proximally away from the sharp tip128 of the cannula 120 to ready the needle assembly 110 for a seconduse.

A needle assembly 210 of a third embodiment is shown in FIG. 12. Partsof the needle assembly 210 of the third embodiment are indicated by thesame reference numerals as for the needle assembly 210 of the firstembodiment, plus “200”. The obturator 226 includes a grip 268 having agenerally tubular portion 269 that extends along the shaft 270 to adistance which fully surrounds the reset member 272. The cross sectionof an opening 273 defined by the tubular portion 269 of the grip 268 iselliptical (or otherwise not the same shape as the cross section of thetubular housing 250). The shaft 270 may be inserted into the tubularhousing 250 and central axial passageway of the cannula 220 as before.However when the grip 268 reaches the tubular housing 250, it engagesthe tubular housing because the elliptical cross sectional shape of theopening 273 does not match the circular cross sectional shape of thetubular housing. This prevents the reset member 272 from beinginadvertently inserted into the tubular housing 250 resulting in anunintended release of the locking mechanism 252 which could cause thecontaminated sharp tip 228 of the cannula 220 to be exposed when theobturator 226 is removed from the central axial passageway.

If it is necessary to de-activate the locking mechanism 252 and withdrawthe safety shield 216 from the sharp tip (not shown) of the cannula 220,the obturator 226 can be reconfigured so that the reset member 272 canmove into the tubular housing 250. This can be accomplished by squeezingon opposite sides of the grip 268, such as indicated by the arrows inFIG. 12. For instance, the points at which the grip 268 is engaged forsqueezing may be the opposite ends of the major axis of the ellipse. Thegrip 268 is formed of an elastic and resilient material that allows theelliptical shape of the opening 273 to become more nearly circular tomatch the shape of the tubular housing 250. Once the shapes are matched,the grip 268 and reset member 272 can be advanced, with the gripreceiving the tubular housing 250 therein and the tubular housingreceiving the reset member 272. The reset member operates to de-activatethe locking mechanism 252 in the same way as described previouslyherein.

Referring now to FIGS. 13 and 14, a modified obturator 226′ of thesecond embodiment is shown. The same reference numerals as used for theneedle assembly 210 of the third embodiment will be used to indicatecorresponding parts in the modified version, with the addition of atrailing prime. It is noted that the tubular housing 250′ of the safetyshield 216′ does not include the membrane 151 of the second embodiment,but otherwise may be of the same construction. However, a membrane (notshown) could be employed in this modified version. The principle ofoperation is similar to the third embodiment. More specifically the grip268′ includes a circular base 268 a ′ from which two projecting members269′ extend a distance greater than the axial extent of the reset member272′. The projecting members 269′ at their free ends are spaced apartacross an opening 273′ a distance less than the diameter of the tubularhousing 250′, but are not sized to fit inside the tubular housing.Accordingly when the obturator shaft 270′ is inserted into the centralaxial passageway of the cannula 220′ a distance which brings the grip268′ into engagement with the tubular housing 250′, the free ends of theprojecting members 269′ engage the tubular housing and prevent furtheradvancement. Thus, the reset member 272′ remains outside the tubularhousing 250′ and the locking mechanism 252′ is not inadvertentlyde-activated.

To allow the locking mechanism 252′ to be de-activated and the safetyshield 216′ withdrawn from the sharp tip of the cannula 220, the grip268′ is provided with wings 273′, each projecting outward from the base268 a′ adjacent to a respective one of the projecting members 269′. Thewings extend generally in the opposite direction from the base 268 a′ asthe projecting members 269′, but also extend radially outward so thatthe wings 273′ diverge from each other. The wings 273′ can be grippedand squeezed as indicated in FIG. 14 so that the free ends of theprojecting members 269′ move apart from each other. The base 268 a′ actsas the fulcrum about which the projecting members 269′ pivot. Thismovement allows the projecting members 269′ to receive the tubularhousing 250′ between them. The reset member 272′ can be advanced intothe tubular housing 250′ to de-activate the locking mechanism 252′ asdescribed previously herein.

Referring now to FIGS. 15 and 16, a needle assembly 310 of a fourthembodiment includes component parts that are indicated by the samereference numerals as used for the needle assembly 310 of the firstembodiment, plus “300”. The needle 314 and safety shield 316 shown inFIG. 16 may have the same construction and operation as thecorresponding parts in the embodiment shown in FIG. 14. The obturator326 of the fourth embodiment includes a grip 368 and a hollowcylindrical portion 375 extending axially from the grip. The resetmember 372 is located on the axially opposite side of the hollow portion375 from the grip 368. A hole 377 in the hollow portion 375 allows itsinterior to communicate with the interior of the tubular reset member372. The shaft 370 includes an obstruction 379 positioned adjacent thefree edge portion 380 of the reset member 372. The shaft 370 extendsthrough the reset member 372 and the hole 377 into the hollow portion375. The end of the shaft 370 is formed with an indicator plaque 381that is wider than the hole 377 in the hollow portion 375 so that theshaft 370 may not be withdrawn from the hollow portion. It will beunderstood that the plaque 381 may have other shapes (e.g., cylindricalwith a larger diameter than the hole 377) without departing from thescope of the present invention. The shaft 370 may be moved axiallyrelative to the reset member 372 and hollow portion 375. A coilcompression spring 374 is located in the tubular reset member 372. Thespring bears against a wall around the hole 377 that separates theinterior of the reset member 372 from the interior of the hollow portion375. The other end of the spring 374 bears against the obstruction 379on the shaft 370. Thus, the spring 374 biases the shaft 370 axiallyoutwardly from the grip 368, hollow portion 375 and reset member 372.

The hollow portion 375 includes a window 383 defined in the hollowportion 375 that is transparent or translucent. The window could beformed simply by an opening in the hollow portion. The other parts ofthe hollow portion 375 are opaque. Thus, when the plaque 381 is in theposition shown in solid lines in FIG. 16, it cannot be seen through thewindow 383. However as will be described, the shaft 370 can be moved tobring the plaque 381 into registration with the window 383 so that theplaque is visible through the window. The plaque 381 may be colored toincrease its visibility.

In operation to remove a bone marrow sample from the cannula 320, theshaft 370 is aligned with the central axial passage of the cannula andinserted. Although no alignment device is shown, a cap like the cap 376shown in FIG. 1, a membrane like the membrane 151 shown in FIG. 8, orsome other suitable aligning device can be used to assist getting theshaft 370 inside the central axial passageway can be used. The shaft 370can be easily advanced through the central axial passageway of thecannula 320 until the obstruction 379 engages the distal end of thecannula. The obstruction 379 is too large to fit into the central axialpassageway and so resistance to further advancement of the shaft 370into the cannula 320 is felt by the medical technician. The shaft 370 issized so that at this point the shaft extends completely through thecannula 320 and the sample (not shown) will have been ejected.

If it is necessary to reset the needle assembly 310 for collectinganother bone marrow sample, then the obturator 326 can be advancedagainst the bias of the spring 374. This allows the reset member 372 toenter the tubular housing 350 of the safety shield 316 for engaging thelocking mechanism 352 to de-activate it as described previously.However, the shaft 370 remains stationary relative to the cannula 320because of the engagement of the obstruction 379 with the cannula. Thiscauses the plaque 381 to move relative to the hollow portion 375 so thatit is brought into registration with the window 383 (shown in phantom inFIG. 16). The appearance of the plaque 381 indicates that the resetmember 372 has been inserted far enough to de-activate the lockingmechanism 352. The technician is given visual confirmation thatde-activation has occurred so that he or she knows that the safetyshield 316 can be withdrawn (i.e., substantially as shown in FIG. 5). Itwill be understood that other ways of confirming de-activation of thelocking mechanism 352 can be used within the scope of the presentinvention.

Referring now to FIGS. 17-24, a medical instrument constructed accordingto the principles of the present invention is shown in the form of abone needle assembly, generally indicated at 410 (see, FIG. 17). Thebone needle assembly includes a handle 412 (broadly, “mountingstructure”), a needle 414 and a cannula safety shield 416, all referencenumbers indicating their subjects generally. The needle 414 includes astylet 418 and a cannula 420 that can receive the stylet. The handle 412includes a first or proximal handle member (indicated generally at 422)mounting the stylet 418, and a second or distal handle member (indicatedgenerally at 424) mounting the cannula 420. It will be understood that aneedle could include only a single component part, or more than twoparts within the scope of the present invention. Similarly, a handlecould be a single part or more than two parts. The mounting structurefor a needle can be other than a handle without departing from thepresent invention. The needle assembly 410 further includes an obturator426, which is described more fully below, that may be used to remove asample captured in the cannula 420.

The cannula 420 has a central axial passage extending the length of thecannula and opening at both ends of the cannula. A distal tip 428 of thecannula 420 is beveled and sharpened, and a proximal end portion of thecannula 420 is received in the distal handle member 424. The stylet 418is solid and includes a sharp distal tip, and a proximal end portion ofthe stylet is received in the proximal handle member 422. The stylet 418can be inserted through the central axial passage opening in theproximal end portion of the cannula 420 and received entirely throughthe axial passage of the cannula so that its sharp distal tip projectsaxially outward from the distal tip 428 of the cannula (as shown in FIG.17). The stylet 418 provides the tool for penetrating the cortical bone,and can be removed from the cannula 420 once the intramedullary canal isaccessed by the needle 414.

The handle 412 formed by the proximal and distal handle members 422, 424has an ergonomic shape that can be comfortably received in a medicaltechnician'ss hand, and allows the technician to easily control theneedle assembly 410 as he or she applies the substantial forces neededto penetrate the bone. More specifically, the top or proximal surface438 of the proximal handle member 422 is rounded in conformance with theshape of the palm of the hand. The bottom or distal surface 440 of thedistal handle member 424 is also rounded, but is undulating in shapethereby forming finger wells 442 for receiving the technician'ssfingers. The form of the handle can be other than described hereinwithout departing from the scope of the present invention. Moreover,needle mounting structure can be other than a handle within the scope ofthe present invention. The proximal and distal handle members 422, 424can be connected together in a suitable manner when the stylet 18 isreceived in the cannula 420, so that the handle 412 acts essentially asa single piece when used to drive the needle 414 through a patient'ssskin and into the bone. The proximal and distal handle members 422, 424can be disconnected and moved apart for removing the stylet 418 from thecannula 420.

The cannula safety shield 416 may be moved to cover the distal tip 428of the cannula 420 after the needle assembly 410 has been used. Thesafety shield 416 includes a generally tubular housing 450 and aninternal locking mechanism (generally indicated at 452 in FIG. 18)capable of releasably locking the tubular housing in position coveringthe distal tip 428 of the cannula 420. The tubular housing 450 has aproximal end closer to the handle 412 and a distal end farther away fromthe handle. A distal end piece of the tubular housing 450 (generallyindicated at 454) includes a funnel-shaped distal end surface 456 of thetubular housing 450 and a central aperture 458 generally aligned withthe central axial passageway of the cannula 420. Although illustrated asa separately formed part attached to the tubular housing 450, the distalend piece 454 and tubular housing may be formed as a single piece ofmaterial. The shape of the distal end surface 456 may be other thandescribed (e.g., lying in a plane perpendicular to the longitudinal axisof the cannula 420) within the scope of the present invention. Threeslots 460 located on the periphery of the tubular using distal end piece454 each extend radially inwardly from the periphery of the end piece atits distal end and also extend axially along the end piece toward theproximal end of the tubular housing 450. The number of slots and theirprecise configuration may be other than described without departing fromthe scope of the present invention. The function of the slots 460 willbe described hereinafter. The tubular housing 450 and handle 412 mayinclude structure to secure the tubular housing in a retracted positionadjacent the handle when not needed. An example of such structure isshown in co-assigned U.S. application SER. NO. 11/146,173, filed Jun 6,2005, the disclosure of which is incorporated herein by reference.

The locking mechanism 452 inside the safety shield 416 comprises acanting member including a base 462 having a hole and a pair of arms 464(only one is shown) extending generally axially from the base. The arms464 are connected together by a U-shaped member 466 at their ends andeach has an upwardly (as oriented in the figures) bent tab 468 (only oneis shown) projecting axially outward from the end. Before the lockingmechanism 452 is activated to lock the tubular housing 450 in position,the ends of the arms 464 ride on the exterior surface of the cannula420. This holds the canting member so that the base 462 is generallyorthogonal so the longitudinal axis of the cannula 420 and the base canmove along the cannula (with the safety shield 416), with the cannulasliding substantially unimpeded through the hole in the base. Once theends of the arms 464 pass the distal tip 428 of the cannula 420, thelocking mechanism 452 is constructed so that the ends of the arms movein a generally radial direction toward an opposite side of thelongitudinal axis of the cannula 420. This causes the base 462 of thecanting member to cant relative to the axis of the cannula 420 so thatthe hole in the base is no longer orthogonal to the axis of the cannula.As a result, the base 462 at the edge of the hole grippingly engages thecannula 420 to lock the safety shield 416 in place. The lockingmechanism 452 further includes angled surfaces 469A, 469B fixed to thetubular housing 450 that can engage the canting member base 462 to keepthe canting member in its canted, locking position upon movement of thetubular housing 450 in either direction relative to the cannula 420. Itwill be understood that a locking mechanism could take on other formsthan shown and described without departing from the scope of the presentinvention.

The safety shield 416 further includes an annular reset plunger 470located inside the tubular housing 450 near its distal end. The resetplunger 470 is movable axially relative to the housing 450 toward theproximal end and includes a frustoconically shaped front surface 472that is engageable with the tabs 468 of the locking mechanism to releasethe locking mechanism, as will be more fully described hereinafter. Aspring 474 engages the reset plunger 470 and biases it toward the distalend of the tubular housing 450. Thus, unless the reset plunger 470 isforcibly moved, it normally does not interfere with the operation of thelocking mechanism 452.

The needle assembly 410 is driven into the bone by grasping the handle412 and pushing the stylet 418 through the skin, underlying tissue andcortical bone. Once this penetration has been achieved, the stylet 418is no longer required. The proximal handle member 422 is disconnectedfrom the distal handle member 424 and moved axially away from the distalhandle member so that the stylet 418 slides out of the central axialpassageway of the cannula 420 while the cannula remains in the bone. Inorder to collect a sample of bone marrow, the distal handle member 424is advanced further into the bone. The sharp tip 428 of the cannula 420cuts into the bone marrow and a sample is received in the central axialpassageway of the cannula. The cannula 420 can then be withdrawn fromthe patient by pulling on the distal handle member 424. The sampleremains lodged in the central axial passageway of the cannula 420 nearthe sharp tip 428. It will be understood that a needle assembly may beused to collect a sample other than of bone marrow within the scope ofthe present invention. Moreover, it is not necessary that a cannula beused to collect any sample. For instance, the cannula could also be usedto withdraw or infuse fluid.

The obturator 426 is used to remove a lodged sample of bone marrow thathas been collected in the central axial passageway of cannula 420. Theobturator 426 includes a grip 478 and a long, thin shaft 480 extendingfrom the grip that is sized to be received in the central axialpassageway of the cannula 420 in generally close fitting relationtherein. The grip 478 is sized and shaped to be grasped by a user (e.g.,between the thumb and pointer finger) for manipulating the obturator426, as will be described. As shown best in FIGS. 22 and 23, a resetkey, generally indicated 482, extends from the grip 478 in the samedirection as the shaft 480, and as illustrated is formed as one piece ofmaterial with the grip. In the illustrated fourth embodiment, the resetkey 482 (broadly, “a reset member”) comprises a tubular shroud 484(broadly, “a support”) defining a central open space 486 sized andshaped to receive a portion of the tubular housing 450 therein. Althoughshown as a solid tubular piece of material with an open end, the shroud484 need not be solid around its circumference within the scope of thepresent invention. Three elongate ribs 488 formed on an inner wall 490of the tubular shroud 484 extend generally parallel to the axis of theshroud and are arranged for reception in the slots 60 of the tubularhousing 450 as will be described. It will be appreciated that a resetkey (not shown) may not be part of an obturator (i.e., the reset keywould not include a shaft like shaft 480) without departing from thescope of the present invention.

FIG. 18 illustrates the initial position of the obturator 426 with theshaft 480 entering the distal end of the tubular housing 450. The freeend of the shaft 480 has not yet entered the central axial passageway ofthe cannula 420 or the aperture 458 of the distal end piece 454. Thefunnel-shaped surface 456 of the distal end piece 454 guides the shaft480 toward the aperture 458 that is aligned with the central axialpassageway of the cannula 420, thereby facilitating reception of theshaft in the passageway. The grip 478 is pushed to advance the shaft 480through the aperture 458 in the funnel-shaped surface 456 and into thecentral axial passageway, which pushes the sample toward the proximalend of the central axial passageway. The shaft 480 is advanced until itprotrudes out of the proximal end of the central axial passageway,thereby pushing the sample (not shown) out of the cannula 420 where itcan be collected in a Petri dish or other suitable container. Therelative location of the tubular shroud 484 and safety shield 416 are inthis position are illustrated in FIG. 19. As the shaft 480 is advanced,it slides through the aperture 458 in the distal end piece 454. Thelocking mechanism 452 remains engaged so that the safety shield 416 doesnot move and the sharp tip 428 remains covered.

The technician may observe the sample ejected from the central axialpassageway of the cannula 420. If it is determined that the sample issatisfactory, the obturator 426 can be pulled so that the shaft 480slides back through and out of the cannula 420. The needle assembly 410can be discarded, or possibly but less likely, cleaned and sterilizedfor a subsequent use. If the sample is not satisfactory, however, itwill be necessary to obtain a second sample from the same patient. Thiscan be done using the same needle assembly 410, but the tubular housing450 is locked in place by the locking mechanism 452 over the sharp tip428 of the cannula 420. The tubular housing 450 needs to be moved awayfrom the tip 428 before the needle assembly 410 can be used to obtain asecond sample.

The obturator 426 of the present invention is particularly adapted topermit the safety shield 416 to be released and moved back from thesharp tip 428 of the cannula 420. It should be understood, however, thata device other than an obturator 426 incorporating the resetting, orunlocking, features of the obturator described herein, but notfunctioning as an obturator, is also contemplated as within the scope ofthe present invention. From the position shown in FIG. 19, the grip 478can be advanced toward the tubular housing 450 so that the ribs 488 arereceived into the corresponding peripheral slots 460 in the tubularhousing 450. It will be necessary to align the ribs 488 withcorresponding ones of the slots 460 before the ribs may enter the slots.The slots 460 and ribs 488 may be shaped and/or arranged to make thiseasier or harder to accomplish as desired. In the illustratedembodiment, the three slots 460 and three ribs 488 are all the same sizeand shape and located at 120 degree intervals. This arrangement makes itrelatively easy to align the obturator 426 and safety shield 416 so thatthe ribs 488 will be received in the slots 460. However, as statedpreviously, other arrangements and configurations are envisioned. Forexample and without limiting the breadth of the present disclosure, theslots 460 and ribs 488 can be arranged at unequal intervals. Moreover,the slots 460 and ribs 488 may have different sizes so that the ribswill be received in the slots in only one relative orientation of theobturator 426 and the safety shield 416. Those of ordinary skill in theart will appreciate other possible configurations and/or arrangements.The bias of the spring 474 resists further advancement of the ribs 488and hence of the obturator 426. This provides a tactile signal to thetechnician that the obturator shaft 480 has been inserted far enoughinto the central axial passageway of the cannula 420 to remove thesample, and that further insertion will result in release of the lockingmechanism 452.

If the safety shield 416 is to be reset to expose the sharp tip 428 ofthe cannula 428, the grip 478 can be advanced toward the tubular housing450 so that the ribs 488 move into the slots 460 and push the resetplunger 470 against the bias of the spring 474 axially toward theproximal end of the tubular housing 450. The front surface 472 of thereset plunger 470 engages the tabs 468 of the canting member moving thearms 464 back to a position more nearly parallel to the longitudinalaxis of the cannula 420. This moves the base 462 of the canting memberto a position substantially orthogonal to the longitudinal axis of thecannula 420 so that the cannula can once again slide freely through thehole in the base (FIG. 20). The locking mechanism 452 is therebyreleased. Thus as shown in FIG. 21, the tubular housing 450 can begrasped to pull back the safety shield 416 toward the distal housingmember 424 so that the sharp tip 428 of the cannula 420 is once againexposed. The obturator shaft 480 can be removed and the stylet 418 canbe reinserted into the cannula 420 for a second collection of a sample.When the ribs 488 move back out of the slots 460, the spring 474 movesthe reset plunger 470 back toward the distal end of the tubular housing450 so that the locking mechanism 452 is again free to operate forlocking the safety shield 416 over the sharp tip 428 of the cannula 420.

Referring now to FIGS. 25 and 26, a needle assembly of a fifthembodiment is shown. Parts of the needle assembly of the fifthembodiment are given the same reference numerals as the correspondingparts of the needle assembly of the fourth embodiment, plus “100”. Asafety shield 516 may have substantially the same construction as thesafety shield 516. In particular, the shield 516 includes a tubularhousing 550 having peripheral slots 560, as in the fourth embodiment. Anobturator 526 and reset key 582 also have similar constructions (e.g.,including ribs 588) as in the fourth embodiment. However, a tubularshroud 584 of the fifth embodiment has a length which is sufficientlygreat so that a central open space 586 of the shroud can receivesubstantially the entire tubular housing 550. Preferably at least amajority of the tubular housing 550 is received in the open space 586 ofthe shroud 584. The operation of ribs 588 associated with the tubularshroud 584 to release a locking mechanism 552 may be as described forthe fourth embodiment. However by receiving tubular housing 550 in thecentral open space 586 of the shroud 584, the tubular housing isshielded from being inadvertently grasped as the obturator is pulledaway from the safety shield so that the safety shield 516 is notunintentionally pulled off of the cannula 520, or otherwise prematurelyremoved from the needle. As best seen in FIG. 27, the peripheral edge ofa distal end piece 554 of the tubular housing 550 is shaped to includeedge segments 592 arranged at converging angles to funnel the ribs 588into the slots 560 when the ribs engage the distal end piece. Becausethe ribs 588 are located deep inside the tubular shroud 584 at thebottom of the open space 586, alignment of the ribs with the slots 560could be difficult. However, the shaped peripheral edge segments 592engage the ribs 588 and urge the rotation of the obturator 526 toproperly orient the reset key 582 so that the ribs move into the slots560.

Referring now to FIGS. 28-35, a medical instrument of a sixth embodimentis shown in the form of a bone needle assembly, generally indicated at610 (FIG. 28). The bone needle assembly includes a handle 612 (broadly,“mounting structure”), a needle 614 and a cannula safety shield 616, allreference numbers indicating their subjects generally. The needle 614includes a stylet 618 and a cannula 620 that can receive the stylet. Thehandle 612 includes a first or proximal handle member (indicatedgenerally at 622) mounting the stylet 618, and a second or distal handlemember (indicated generally at 624) mounting the cannula 620. It will beunderstood that a needle could include only a single component part, ormore than two parts within the scope of the present invention.Similarly, a handle could be a single part or more than two parts. Themounting structure for the needle 614 can be other than a handle withoutdeparting from the present invention. The needle assembly 610 furtherincludes an obturator 626, which is described more fully below, that maybe used to remove a sample captured in the cannula 620.

The cannula 620 has a central axial passage extending the length of thecannula and opening at both ends of the cannula. A distal tip 628 of thecannula 620 is beveled and sharpened. A proximal end portion of thecannula 620 is received in the distal handle member 624. The stylet 618is solid and includes a sharp distal tip, and a proximal end portion ofthe stylet is received in the proximal handle member 622. The stylet 618can be inserted through the axial passage opening in the proximal endportion of the cannula 620 and received entirely through the axialpassage of the cannula so that its sharp distal tip projects axiallyoutward from the distal tip 628 of the cannula. The stylet 618 providesthe tool for penetrating the cortical bone, and can be removed from thecannula 620 once the intramedullary canal is accessed by the needle 614.

The handle 612 formed by the proximal and distal handle members 622, 624has an ergonomic shape that can be comfortably received in a medicaltechnician's hand, and allows the technician to easily control theneedle assembly 610 as he or she applies the substantial forces neededto penetrate the bone. More specifically, the top or proximal surface638 of the proximal handle member 622 is rounded in conformance with theshape of the palm of the hand. The bottom or distal surface 640 of thedistal handle member 624 is also rounded, but is undulating in shapethereby forming finger wells 640A for receiving the technician'sfingers. The form of the handle can be other than described hereinwithout departing from the scope of the present invention. The proximaland distal handle members 622, 624 can be connected together in asuitable manner when the stylet 618 is received in the cannula 620, sothat the handle 612 acts essentially as a single piece when used todrive the needle 614 through a patient's skin and into the bone. Theproximal and distal handle members 622, 624 can be disconnected andmoved apart for removing the stylet 618 from the cannula 620.

The cannula safety shield 616 may be moved to cover the distal tip 628of the cannula 620 after the needle assembly 610 has been used. Thesafety shield 616 includes a generally tubular housing 650 and aninternal locking mechanism (generally indicated at 652 in FIG. 29)capable of releasably locking the tubular housing in position coveringthe distal tip 628 of the cannula 620. As shown best in FIG. 635, thedistal end of the tubular housing 650 includes a funnel-shaped guide 653leading to an opening 654 directed toward the central axial passagewayof the cannula 620. The tubular housing 650 may have any shape that issuitable for hindering access to the sharp tip 628. The tubular housing650 need not be solid or circular in cross section within the scope ofthe present invention. The tubular housing 650 and handle 612 mayinclude structure to secure the tubular housing in a retracted positionadjacent the handle when not needed. An example of such structure isshown in co-assigned U.S. application SER. NO. 11/146,173, filed Jun 6,2005, the disclosure of which is incorporated herein by reference.

The locking mechanism 652 inside the safety shield 616 comprises acanting member including a base 656 having a hole and a pair of arms 660(only one is shown) extending generally axially from the base. The arms660 are connected together by a U-shaped member 662 at their ends andeach has an upwardly (as oriented in the figures) bent tab 664 (only oneis shown) projecting axially outward from the end. Before the lockingmechanism 652 is activated to lock the tubular housing 650 in position,the ends of the arms 660 ride on the exterior surface of the cannula620. This holds the canting member so that the base 656 is orthogonal sothe longitudinal axis of the cannula 620 and the base can move along thecannula (with the safety shield 616), with the cannula sliding unimpededthrough the hole in the base. Once the ends of the arms 660 pass thedistal tip 628 of the cannula 620, the locking mechanism 652 is weightedso that the ends of the arms move in a generally radial direction towardan opposite side of the longitudinal axis of the needle 614. This causesthe base 656 of the canting member to cant relative to the axis of theneedle 614 so that the hole in the base is no longer orthogonal to theaxis of the cannula. As a result, the base 656 at the edge of the holegrippingly engages the cannula 620 to lock the safety shield 616 inplace. It will be understood that a locking mechanism could take onother forms than shown and described without departing from the scope ofthe present invention. Moreover, a canting member may take on otherconfigurations (e.g., having only a single arm) within the scope of thepresent invention.

The needle assembly 610 is driven into the bone by grasping the handle12 and pushing the stylet 618 through the skin, underlying tissue andcortical bone. Once this penetration has been achieved, the stylet 618is no longer required. The proximal handle member 622 is disconnectedfrom the distal handle member 624 and moved axially away from the distalhandle member so that the stylet 618 slides out of the central axialpassageway of the cannula 620 while the cannula remains in the bone. Inorder to collect a sample of bone marrow, the distal handle member isadvanced further into the bone. The sharp tip 628 of the cannula 620cuts into the bone marrow and a sample is received in the central axialpassageway of the cannula. The cannula 620 can then be withdrawn fromthe patient by pulling on the distal handle member 624. The sampleremains lodged in the central axial passageway of the cannula 620 nearthe sharp tip 628. It will be understood that a needle assembly may beused to collect a sample other than of bone marrow within the scope ofthe present invention.

The obturator 626 is used to remove a lodged sample of bone marrow thathas been collected in the central axial passageway of cannula 620. Theobturator 626 includes a grip 668 and a long, thin shaft 670 extendingfrom the grip that is sized to be received in the central axialpassageway of the cannula 620 in generally close fitting relationtherein. The grip 668 is sized and shaped to be grasped by a user formanipulating the obturator 626, as will be described. As shown best inFIGS. 34 and 35, a reset member, generally indicated at 672, extendsfrom the grip 668 in the same direction as the shaft 670. In theillustrated sixth embodiment, the reset member 672 comprises projectingportions 678 (e.g., three projecting portions) extending from the grip668 in the same direction as the shaft 6670. The grip 668 furthercomprises a protective collar 680 extending from the grip 668 tosurround the projecting portions 678 and protect the projecting portionsfrom damage. The collar 680 is further adapted to slidably receive thetubular housing 650 in close-fitting relation for proper alignment ofthe projecting portions 678, as will be discussed in greater detailbelow with respect to FIG. 31.

FIG. 629 illustrates an initial position of the obturator 626 with theshaft 670 entering the distal end of the tubular housing 650. The freeend of the shaft 670 has not yet entered the central axial passageway ofthe cannula 620. As shown best in FIG. 635, the distal end of thetubular housing 650 includes the funnel-shaped guide 653 (broadly, “endwall”) for guiding the shaft 670 toward the opening 654 in thefunnel-shaped guide leading to the central axial passageway of thecannula 620. The grip 668 is pushed to advance the shaft 670 through thefunnel-shaped guide 653 and into the central axial passageway, whichpushes the sample toward the proximal end of the central axialpassageway. Referring to FIG. 30, the shaft 670 is advanced until itprotrudes out of the proximal end of the central axial passageway,thereby pushing the sample (not shown) out of the cannula 620 where itcan be collected in a Petri dish or other suitable container. As theshaft 670 is advanced, it slides through the funnel-shaped guide 653 atthe distal end of the tubular housing 650. The locking mechanism 652remains engaged so that the safety shield 616 does not move. In theposition shown in FIG. 30, free ends of the projecting portions 678engage the funnel-shaped guide 653. Thus, the technician experiences aresistance to further inward movement of the shaft 670 into the centralaxial passageway of the cannula 620 because the funnel-shaped guide 653is restricting movement of the projecting portions 678 of the obturator626. As would be readily understood by one skilled in the art, thedistal end of the tubular housing 650 may be other than funnel-shapedaccording to the present invention. For example, the distal end may begenerally orthogonal to the central axial passageway (or concave orconvex) with an opening leading to the central axial passageway of thecannula 620.

The technician may observe the sample ejected from the central axialpassageway of the cannula 620. If it is determined that the sample issatisfactory, the obturator 626 can be pulled so that the shaft 670slides back through and out of the cannula 620. The needle assembly 610can be discarded, or possibly but less likely, cleaned and sterilizedfor a subsequent use. If the sample is not satisfactory, however, itwill be necessary to obtain a second sample from the same patient. Thiscan be done using the same needle assembly 610, but the tubular housing650 is locked in place by the locking mechanism 652 over the sharp tip628 of the cannula 620. The tubular housing 650 needs to be moved awayfrom the tip 628 before the needle assembly 610 can be used to obtain asecond sample.

The obturator 626 of the present invention is particularly adapted topermit the tubular housing 650 to be released and moved back from thesharp tip 628 of the cannula 620, without requiring the technician toremove the contaminated obturator from the cannula. This allows theobturator 626 to be used to both eject the sample and reset the safetyshield 616 without utilizing an additional resetting device. This isadvantageous because the technician can eliminate the extra steps ofremoving the obturator, locating the resetting device, and inserting theresetting device. Moreover, removing the obturator 626 is undesirablebecause it is contaminated and its removal may contaminate surroundingsurfaces. It should be understood, however, that even with the benefitsof an obturator having resetting capabilities, a device other than anobturator 626 incorporating the resetting, or unlocking, features of theobturator described herein, but not functioning as an obturator, is alsocontemplated as within the scope of the present invention. From theposition shown in FIG. 30, the grip 668 can be advanced toward thetubular housing 650 so that the projecting portions 678 are receivedinto a corresponding number of holes 690 (see FIG. 35) in thefunnel-shaped guide 653 of the tubular housing. The holes 690 have agenerally rectangular shape corresponding to the cross-sectional shapeof the projecting portions 678, although other hole shapes are alsocontemplated as within the scope of the claimed invention. In theexample shown, the holes 690 have a different shape than the opening 654to encourage a user of the device to correctly insert the cylindricalshaft 670 into the opening and the projecting portions 678 into theholes. The grip 668 and projection portions 678 are rotatable togetherwith respect to the tubular housing 650 about a longitudinal axis of theshaft 670, whereby the obturator 626 may be rotated to a particularangular orientation relative to the tubular housing so that theprojecting portions precisely align with respective holes 690. Thus,only at this particular angular orientation will the projecting portions678 be capable of releasing the locking mechanism 652. Guiding structure(not shown) could be provided to guide the projecting portions 678 intothe holes 690.

As depicted in the example of FIG. 35, three holes 690 of the tubularhousing 650 are arranged in a pattern having a first order rotationalsymmetry. In other words, the holes 690 of the tubular housing 650 (FIG.35) and the projecting portions 678 of the obturator 626 (FIGS. 33 and34) will only fit together in one angular orientation. In anotherexample (not shown), the holes 690 and projection portions 678 may belocated at 120 degree intervals relative one another, providing thirdorder rotational symmetry, whereby the holes of the tubular housing 650and the projecting portions of the obturator 626 may fit together inthree distinct angular orientations. Other orders of rotational symmetry(e.g., second, fourth, fifth, etc.) including a fewer or greater numberof projection portions 678 and holes 690 are also contemplated as withinthe scope of the claimed invention. Generally, a higher order ofrotational symmetry provides more angular orientations where the holes690 of the tubular housing 650 and the projecting portions 678 of theobturator 626 will fit together for unlocking the safety shield 616. Itshould be understood that the cross-sectional areas and shapes of theprojecting portions 678 and holes 690 need not be the same, as long asthe holes are large enough to receive corresponding projecting portions.Other means for requiring a particular orientation of the obturator 626with respect to the tubular housing 650 for releasing the lockingmechanism 652 are also contemplated as within the scope of the claimedinvention (e.g., corresponding collar and tubular housing shapes, matingchannels, etc.).

The safety shield 616 further comprises an unlocking mechanism,generally indicated 696, for selective, movable engagement with thelocking mechanism 652 for releasing the locking mechanism to permit thetubular housing 650 to move away from the sharp end 628 of the cannula620. The unlocking mechanism 696 is movable between a first position inwhich it is free to lock the safety shield 616 in position relative tothe sharp end 628 of the cannula 620 and a second position in which theunlocking mechanism releases the locking mechanism 652 to permitmovement of the safety shield relative to the sharp end of the cannula.In one example, the unlocking mechanism 696 comprises a generally rigidbody such as a cylindrical sleeve 698, or other annular shape, slidablyenclosed within and supported by the tubular housing 650 for movementrelative to the tubular housing and the locking mechanism 652. In theexample shown, the sleeve 698 moves freely within the tubular housing650, although connections between the sleeve and the tubular housing orthe sleeve and the base 656 are also contemplated as within the scope ofthe invention. Moreover, the sleeve 698 may be biased away from the base656 to inhibit inadvertent release of the locking mechanism 652. Withthe projecting portions 678 aligned with the holes 690, the grip 668 canbe advanced toward the tubular housing 650 so that the projectingportions 678 pass through the holes 690 and into the tubular housing toengage the sleeve 698 for movement of the sleeve toward the base 656 ofthe canting member. During advancement of the grip 668, the collar 680slidably, yet snugly, receives the tubular housing 650 in relativelyclose engagement to minimize canting of the collar with respect to thetubular housing, thereby facilitating proper alignment of the projectingportions 678 within the holes 690. Moreover, as a leading edge freeportion of the sleeve 698 engages the base 656 of the canting member,the sleeve wedges the base of the canting member up to a position inwhich the base is again substantially orthogonal to the axis of thecannula 620, as shown in phantom in FIG. 31. This positions the hole inthe base 656 so that the cannula 620 can slide easily through thecanting member. In another example, the sleeve 698 may engage anotherportion of the canting member (e.g., the bent tab 664) to reset thecanting member, without departing from the scope of the claimedinvention.

Thus, as shown in FIG. 32, the tubular housing 650 can be grasped topull back the safety shield 616 toward the distal housing member 624 sothat the sharp tip 628 of the cannula 620 can be exposed. The obturatorshaft 670 can be removed, as shown in phantom in FIG. 32, and the stylet618 can be reinserted into the cannula 620 for a second collection of asample. It will be appreciated that the arrangement of the projectingportions 678 and holes 690 such that only one angular orientation of theobturator 626 will unlock the locking mechanism 652 inhibits theaccidental release of the locking mechanism. The technician mustintentionally align the projecting portions 678 and holes 690 tode-activate the locking mechanism 652. In this manner, the funnel-shapedguide 653 acts as a reset inhibitor by only permitting de-activation thelocking mechanism 652 with proper alignment of the projecting portions678 and the holes 690.

As would be readily understood by one skilled in the art, the grip 668may additionally comprise a cavity 700 opposite the open collar 680 andprojecting portions 678 for accommodating the portion of the cannula 620extending from the distal end of the tubular housing 650 when theprojecting portions have fully extended into the holes 690 of thetubular housing.

Referring to FIGS. 36-63, there are illustrated additional embodimentsof the present invention incorporating a resettable feature. As shown inFIGS. 36-43, an obturator 761 having reset geometry 762 (“a resetmember”) interacts with a reset element 763.

The obturator 761 may have a handle 770. The handle 770 may include acavity 765 to protect the needle 766 during resetting. The obturator 761may also include a funnel 764 to guide the obturator 761 through thesafety shield 769 to the inner diameter of the needle 766. The funnel764 may include locating surfaces 767 on the housing to facilitateguiding. The funnel 764 is slidable along the obturator 761 such thatthe funnel 764 allows the obturator 761 to pass through the funnel 764.The funnel 764 may be a separate piece. The obturator 761 may alsoinclude a blocking element 768 positioned to prevent resetting. Theblocking element 768 may also be movable relative to the obturator 761so that the blocking element 768 may receive the safety shield 769through the blocking element to allow the resetting geometry 762 tointeract with the reset element 763. The means for moving the blockingelement 768 includes, but is not limited to, levers, hinges, buttons,locks, snaps, detents, etc.

In this embodiment the obturator 761 is configured such that after theobturator 761 is through the needle 766 and expels a sample, theblocking element 768 in a blocking position engages the safety shield769 and precludes the resetting geometry 762 from interacting with thereset element 763.

The blocking element 768 is then moved to a non-blocking position suchthat the resetting geometry 762 interacts with the reset element 763.The resetting geometry 762 interacts with the reset element 763 suchthat the binding member 760 is released from a locked position. Thisallows the safety shield 769 to be ready for reuse. It is alsoenvisioned that the resetting geometry 762 may be placed in otherlocations on the obturator 761 including, but not limited to, theopposite end of the obturator 761.

As illustrated in FIGS. 44-47, a funnel 792 guides an obturator 791 tothe inner diameter of a needle 796. The funnel 792 may be configuredsuch that it allows for a locking or friction fit to the needle 796. Thefunnel 792 may also be configured such that it incorporates locatingfeatures 793 on the safety shield 799 for guiding the obturator 791 tothe inner diameter of the needle 796. The locating features 793 on thesafety shield 799 may also be configured such that a desirable fit isaccomplished to maintain position. Such fit interfaces include, but arenot limited to, snap fit, friction fit, detents, etc. The option to usethe funnel 792 with or with out the safety shield 799 may be desirableso that clinicians may choose to use the funnel 792 with the safetyshield 799 protecting the contaminated sharp to guide an obturator 791to the inner diameter of the needle 796. This also allows forconventional use without safety devices.

Referring to FIGS. 48-63, in certain applications it may be desirable tofunnel an obturator through the needle device. It may also be desirableto incorporate this guiding member in a safety shield, which may requireactivation of the safety shield prior to using the funnel. Furthermore,it may be desirable to reset a binding member that protects acontaminated sharp (e. g. medical needle, stylet, etc.).

One embodiment illustrates a guiding member 802 that is integral to thesafety shield 801. The guiding member 802 includes an interface of aparticular geometry that allows for guiding a through-the-needle device,such as an obturator 803, etc. The guiding member 802 is configured suchthat the through-the-needle device 803 cannot interfere with the lockingmechanism 804 in the safety shield 801. Other embodiments include ageometry that continues to allow for guiding of guiding member 802, butwhich also provides reset areas 806 for the safety shield 801.

FIGS. 50-51 show a guiding member 812 having flexible members 815allowing the guiding member 812 to change sizes. This allows for guidingof a through the needle device 813 (e.g., an obturator). The flexiblemembers 815 also allow for a larger opening that provides a reset area816. The reset area 816 is an area that will allow reset geometry 817(“reset member”), or other geometry that interacts with the resetgeometry 817, to be brought into a position such that it interacts withthe reset element 818 to allow the locking mechanism 814 to be releasedfrom binding the safety shield 811 in place on the needle. This allowsfor the safety shield 811 to be ready for reuse.

As shown in FIGS. 52-54, another embodiment includes a guiding member822 having adjustable members 825 that can be positioned by apositioning member 829. The adjustable members 825 may be either rigidor flexible. The positioning member 829 may include, but is not limitedto, a sleeve, button, lever, collar, or other member intended tointeract with the adjustable members 825. The adjustable members 825 areconfigured such that the positioning member 829 interact with theadjustable members 825 causing the adjustable members 825 to bepositioned so as to guide a through-the-needle device 823 (e.g., anobturator). The adjustable members 825 may be configured such that atighter guiding member 822 may be obtained, than otherwise may fitaround the needle 820. The positioning member 829 may contain gripsurfaces 824. The grip surfaces 824 may be configured such that uponsubsequent activation of the safety shield 821, the positioning member829 will position the flexible members 825 upon activation. Thepositioning member 829 may also be configured such that the positioningmember 829 may be repositioned wherein the adjustable members 825provide a reset area 826.

As seen in FIGS. 55-57, another embodiment is illustrated wherein aguiding member 832 is integrated with the obturator 831. The guidingmember 832 may be configured such that it remains attached to theobturator 831. The guiding member 832 may also be configured such thatit is slidable along the obturator 831.

This embodiment depicts the guiding member 832 having a spring 833 (seeFIGS. 56-57). The spring 833 may include, but is not limited to, aspring, folded plastic, telescoping features, line, wire, etc. It isconfigured such that the natural resting position of the guiding member832 is at the end of the obturator 831. This allows for guiding of theobturator 831. The guiding member 832 is configured such that when theneedle 830 is brought toward the obturator 831, the guiding member 832guides the needle to the center. This guiding takes place with littleresistance. When the needle 830 contacts the center of the guidingmember 832, there are locking surfaces 834 configured such that theneedle 830 tends to lock onto the guiding member 832, such as forexample a luer taper. After the needle 830 is locked onto the guidingmember 832, continued motion tends to make the guiding member 832 slidealong the obturator 831. The obturator 831 is then guided into theneedle 830 and expels the sample.

In another embodiment shown in FIGS. 58 and 59, a shield 832′ similar tothe guiding member 832 is slidably secured to the obturator 831′ so thatthe obturator can slide through the guiding member while compressing aspring 833′. The shield 832′ substantially covers the sharpened end ofthe needle 830′ to protect the user from an accidental stick. The spring833′ keeps the shield 832′ in place on the end of the needle 830′throughout the operation of removing the sample illustratedschematically in FIGS. 58 and 59. The shield 832′ may or may not have aguiding function for guiding the obturator 831′ into the centralpassageway of the hollow needle 830′. The sharpened tip of the needle830′ is received in a tapered opening that also passes a shaft 831A′ ofthe obturator 831′ through the shield 832′, but is blocked from passingthrough the shield by the size of the opening. The shaft 831A′ of theobturator 831′ will enter the central passageway of the needle 830′ asthe two parts are pushed further together (see, FIG. 59). However, theshield 832′ remains in place, held by the sharpened end of the needle830′ and the bias of the spring 833′. As the obturator 831′ is removedfrom the needle 830′, the bias of the spring 833′ keeps the shield 832′against the sharpened end of the needle so that the sharpened end issubstantially covered at all times during the operation of removing thesample. Once the shaft 831A′ of the obturator 831′ is completelywithdrawn from the needle 830′, further separation will move the shield832′ off of the sharpened end of the needle so that the needle can beused again. Preferably, the shield 832′ is retained on the obturatorshaft 831A′ at all times.

As shown in FIGS. 60-61, the obturator grip or handle 845 may beconfigured such that reset geometry (or a “reset member”) in the form ofthree pins 847 is integrated onto the obturator handle 845. Theobturator handle 845 may also contain locking surfaces 844 configuredsuch that the needle 840 tends to lock onto the obturator handle 845.The number of pins may be other than three within the scope of thepresent invention.

Other embodiments include modifications to the end sensing member 852(see FIG. 62). The end sensing member 852 includes needle communicatingsurfaces 851 that rides on the needle 850 and provides a force to resistbinding. When the geometry of the needle 850 changes (e. g., end of theneedle, needle grind, needle taper, etc.), the end sensing member 852senses the change of the needle 850 and binding is no longer resisted.Changing the needle 850 geometry includes, but is not limited to, angledsurfaces, notched surfaces, bumps, or any surface intended to amplifyend sensing. Angled surfaces 854 are shown in FIG. 62. The angledsurfaces 854 are configured such that a slight needle 850 geometrychange causes the angled surfaces 854 to translate dramatically. This isdue to the geometry condition that exists from the angled surfaces 854.

Another embodiment is shown in FIG. 63 having a separate needlecommunicating surface 861. This needle communicating surface 861 appliesa frictional force to the needle 860. This force is used in combinationwith needle communicating members 862 to oppose binding. The frictionalforce that opposes binding on the needle 860 is available for geometrychanges in the needle 860 that prevent the friction forces from beingapplied (e. g., needle taper, needle grind, end of the needle, etc.).

Referring now to FIGS. 64 and 65, a safety shield 916 of a needleassembly is shown to comprise a tubular housing 950 containing a lockingmechanism 952 substantially similar to the locking mechanisms (52, etc.)described above. The safety shield 916 can be used with needleassemblies as shown and described previously herein. In the embodimentof FIGS. 64 and 65, a reset member 972 comprises an annular engagingportion 972A and a pair of slides 972B (broadly, “actuating members”).The engaging portion 972A is located inside the tubular housing 950 andthe slides 972B are located on the exterior of the housing. Theconnection of the engaging portion 972A with the slides 972B occursthrough respective slots 973 in the tubular housing. Moving the slides972B in a direction that is generally parallel to the outer surface ofthe tubular housing 950 toward the proximal end of the tubular housingmoves the engaging portion 972A into engagement with a base 956 of thelocking mechanism 952. The engaging portion 972A can push the base 956so that the locking mechanism 952 releases its lock on the needle (notshown), allowing the safety shield 916 to be moved away from a sharpenedend of the needle so that the needle can be reused. As described forearlier embodiments, in the release position the locking mechanism base956 is more nearly perpendicular to the longitudinal axis of the needleand arms 960 of the locking mechanism are more nearly parallel to thelongitudinal axis of the needle. The reset member 972 can be biased in adirection out of engagement with the locking mechanism 952 so that itdoes not interfere with normal operation of the locking mechanism.

When introducing elements of the present invention or the preferredembodiment(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements. Moreover, the use of “up”, “down”, “top” and “bottom” andvariations of these terms is made for convenience, but does not requireany particular orientation of the components.

As various changes could be made in the above without departing from thescope of the invention, it is intended that all matter contained in theabove description and shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense. What is claimedis:

1. An obturator for use with a needle assembly to remove a sample ofbiological material collected in a hollow needle of the needle assembly,the obturator comprising: a grip for holding and manipulating theobturator; a shaft extending from the grip, the shaft being sized andshaped for reception in a central axial passageway of the hollow needlefor pushing the sample out of the central axial passageway; a shieldslidably supported on the shaft for engaging and shielding a sharp endof the hollow needle when the obturator shaft is being inserted into theneedle to remove the sample.
 2. An obturator as set forth in claim 1further comprising a spring supported by the shaft and biasing theshield toward an end of the shaft opposite the grip.
 3. An obturator asset forth in claim 2 wherein the spring is a coil spring and the shaftextends generally through the coil.
 4. An obturator as set forth inclaim 2 wherein the spring engages the grip at one end of the spring andengages the shield at an opposite end for biasing the shield on theshaft away from the grip.
 5. An obturator as set forth in any one ofclaim 1 in combination with the needle assembly.
 6. A needle assemblycomprising: mounting structure; a needle mounted on the mountingstructure and extending outwardly therefrom, the needle having alongitudinal axis, a sharp end and a central axial passageway; a safetyshield associated with the needle and comprising a tubular housinghaving an open end, the tubular housing being adapted for movementrelative to the needle between a stowed position in which the tubularhousing is spaced from the sharp end of the needle and a deployedposition in which the tubular housing covers the sharp end, and alocking mechanism adapted to releasably lock the tubular housing inposition covering the sharp end of the needle; and a reset memberselectively operatively engageable with the locking mechanism of thesafety shield for releasing the locking mechanism to permit the tubularhousing to be move away from the sharp end of the needle; the safetyshield further comprising a resilient membrane substantially coveringthe open end of the tubular housing, the membrane being resilientlydeformable upon engagement with the reset member to permit the resetmember to move into operative engagement with the locking mechanism forreleasing the locking mechanism.
 7. A needle assembly as set forth inclaim 6 wherein the membrane is generally annular and has a centralopening generally in alignment with the central axial passageway of theneedle.
 8. A needle assembly as set forth in claim 7 further comprisingan obturator include a shaft adapted to be received through the centralopening of the membrane for guiding the shaft into the central axialpassageway of the needle.
 9. A needle assembly as set forth in claim 72wherein the reset member is supported by the obturator shaft.
 10. Aneedle assembly comprising: mounting structure; a needle mounted on themounting structure and extending outwardly therefrom, the needle havinga longitudinal axis, a sharp end and a central axial passageway; asafety shield associated with the needle and comprising a tubularhousing, the tubular housing being adapted for movement relative to theneedle between a stowed position in which the tubular housing is spacedfrom the sharp end of the needle and a deployed position in which thetubular housing covers the sharp end, and a locking mechanism adapted toreleasably lock the tubular housing in position covering the sharp endof the needle; and a reset member supported on the safety shield forsliding movement relative to the safety shield generally parallel to aouter surface of the safety shield, the reset member being selectivelyoperatively engageable with the locking mechanism of the safety shieldfor releasing the locking mechanism to permit the tubular housing to bemove away from the sharp end of the needle.
 11. A needle assembly as setforth in claim 10 wherein the reset member includes an engaging portiondisposed in the safety shield and capable of engaging the lockingmechanism to release the locking mechanism.
 12. A needle assembly as setforth in claim 11 wherein the engaging portion is annular in shape andgenerally coaxial with the longitudinal axis of the needle.
 13. A needleassembly as set forth in claim 11 wherein the reset member furthercomprises an actuating portion located on an outer surface of the safetyshield.
 14. A needle assembly as set forth in claim 13 wherein theactuating portion comprises a slide.